Hip joint prosthesis

Abstract

A hip joint prosthesis comprising a femoral stem, adapted for implant into the medullary canal of a human leg femur, said stem having a superior neck portion whose longitudinal axis is arcuate, forming concave and convex portions thereof, and terminating in a globular femoral head, and an acetabular cup, adapted to be attached to a human pelvis. The cup is sized and shaped to rotatingly receive the femoral head. The inferior portion of the cup is relieved by an indentation therein which accommodates the convex contour of the arcuate neck during extension and abduction of the leg. The concave portion of the neck is adapted to arch over and avoid interfering with the superior rim of the cup during hyperflexion of the leg. The indentation in the inferior portion of the cup is intended to receive and accommodate the convex contour of the arcuate neck during extension and abduction of the leg.

I claim:  
     
       1. A hip joint prosthesis comprising, 
       a femoral stem, adapted for implant into the medullary canal of a human femur, said stem having a superior neck whose longitudinal axis is arcuate, forming concave and convex contours, and terminating in a rounded femoral head;  
       an acetabular cup adapted to be attached to a human pelvis, sized and shaped to receive the femoral head for rotating movement therein, wherein an inferior portion of the cup is indented to accommodate the convex contour of the arcuate neck during extension and adduction of the femur;  
       wherein the longitudinal axis of the neck is curved anteriorly of a substantially frontal plane of the stem and laterally of a substantially sagittal plane of the stem.  
     
     
       2. A hip joint prosthesis comprising, 
       a femoral stem, adapted for implant into the medullary canal of a human femur, said stem having a superior neck whose longitudinal axis is curved anteriorly of a plane which is substantially frontal with respect to the implanted stem and laterally of a plane which is substantially sagittal with respect to the implanted femoral stem, forming a neck elbow and a corresponding neck concavity, terminating in a rounded femoral head.  
     
     
       3. The prosthesis of  claim 2  and further comprising an acetabular cup adapted to be attached to the human pelvis, having a concave body sized and shaped to receive the femoral head and bounded by a circumferential rim having a superior portion and an inferior portion, wherein the inferior portion contains an indentation that extends into the body of the cup to accommodate the outside neck elbow of the stem during extension and adduction of the femur.